Winding for electrical apparatus.



No. 776,653. PATENTED DEC. 6, 1904 J, W. FARLEY.

WINDING FOR ELECTRICAL APPARATUS. AYPLIOATION FILED MAR. 16, 1904.

N0 MODEL.

JTW 74 2.? I

W "mill lllllli Ill jalllllllll 5 N 6 8 7 2* 3 a 5 I fl WITNESSES: v //VVE/=/TOR WM 4% va/m A WKRA/EY No, 776,653. Patented December 6, 1904.

UNITED STATES PATENT OFFICE.

JOSEPH W. FARLEY, OF EAST PITTSBURG, PENNSYLVANIA, ASSIGNOR TO IVESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORA- TION OF PENNSYLVANIA.

WINDING FOR ELECTRICAL APPARATUS- SPECIFICATION forming part of Letters Patent No. 776,653, dated December 6, 1904.

Application filed March 16, 1904:. Serial No. 198,506. (No model.)

To all who i ay 0071087: employ flat coils placed side by side in paral- Be it known that I, JosEPII IV. FARLEY, a lel planes, so that if several conductors are 5 citizen of the United States, and a resident of wound in multiple it is desirable and gener- East Pittsburg, in the county of Allegheny ally necessary to wind them one outside of and State of Pennsylvania, have invented a another. It follows from this method of connew and useful Improvement in WVindings for struction that the outer strands have more re- Electrical Apparatus, of which the following sistance than the inner ones, because of their 55 is aspecification. greater lengths, and hence local currents are My invention relates to windings for eleclikely to result. To avoid these difliculties, I

[O trical apparatus, and particularly to the windhave devised a coil of such construction that ings employed in transformers. the parallel strands composing the conductor It has for its object to provide acoil of such are approximately of the same length, and 60 construction that local and eddy currents may hence have substantially the same resistance. be reduced to a minimum and the resistances Referring now to Fig. 1, in which a coil 1,

5 of parallel paths maybe made approximately composed of three turns or sections 2, 3, and

equal. 4, is represented, each turn of the coil is com My invention is illustrated in the accompaposed of four strands 5, 6, 7, and 8 of covered 5 nying drawings, in which or insulated wire wound in multiple and one Figure 1 is aface view of a coil constructed outside of another. It is to be understood,

in accordance therewith, a portion thereof however, that the number of conductors and being broken away to show the internal conthe number of turns shown are selected merely struction; and Fig. 2 is an end view of the as examples and that any other numbers with- 70 coil shown in Fig. 1. in practicable limits may be employed, if de- Transformers employed for transforming sired.

comparatively small currents at high voltages In order that the strands may all be of apinto very large currents at low voltages have proximately the same length, the coil is conbut few turns in the secondary winding, and structed as follows: The four strands 5, 6, '7, '7 5 consequently the conductor must have a large and 8 are bent or wound in aclockwise direccross-sectional area. If the conductor contion in a single plane into substantially rec- 0 sists of only a single bar or strap wound tangular form beginning at the point 9 and edgewise, the electrical path at the outer edge ending at the corner 13. The strands are thereof is of greater length than that at the bent from that point laterally to the corner 0 inner edge, and local currents may therefore 10 and thence parallel to the corresponding be produced in the conductor, the effect of side of the turn or section 2 to the corner 11.

3 5 which is to cause undue heating and possible From the corner 11 the strands are bent at an injury to adjacent parts and also to absorb angle somewhat more than ninety degrees, power, and thus reduce the efliciency of the and each is given a return bend at such point 8 5 transformer. that all may cross each other and be reversed It is well known that excessive eddy-curas regards their respective distances from the rents may be avoided'by employing a pluralcenter of the coilt'. a, the strand 5, which ity of relatively small insulated conductors is on the outside between the point 9 and its wound in parallel instead of a single conductor return bend 14:, becomes the inside strand, the 9 having the same cross-sectional area, and it strands 6 and 7 are changed at their return is by similar means that I am enabled to probends 15 and 16 from numbers two and three vide a conductor in which the production of from the outside to numbers two and three local currents is reduced to a minimum. from the inside of the coil, and strand 8 is In the construction of transformers of the changed at its return bend 17 from the inside shell type it is a customary practice to to the outside of the coil. From the corner 12 the strands are continued to the corner 13 and are then bent laterally to the point 10 and from that point are bent parallel to the section 2 to the point 9, Where connection is made with the external circuit.

It will be understood from the foregoing description and the accompanying illustration that all of the strands are of substantially the same length, since one and one-half turns of each strand have a complementary relation to the other one and one-half turns as regards distance from the center of the coil. It is to be observed that the strands are not twisted, but are simply deflected to form the return bends, and that the lateral space required by the crossovers is only twice the width of a single strand, because the crossovers are distributed. The turn or section in which the crossovers occur is generally interposed between other turns, and in order to avoid bulging the coil laterally and minimize the space occupied by the assembled coils in the same direction the portion of the turn 3 containing the crossovers is extended beyond the corresponding ends of the adjacent turns 2 and l, so that the extra space occupied by the bulged or enlarged portions occurs at the end of the coil a place Where space is most available.

Although one set of crossovers per coil Will generally be found suflicient, thenumber is not limited to one, and if it is desired to only partially prevent the generation of local currents the crossovers may be located at some place other than the middle of the total lengths of the strands. The strands of wire may be of different form in cross-section, and the coil may be of any other shape or dimensions within practicable limits, if desired.

It is to be understood that my invention is not limited to coils for transformers of the shelltype alone, but may be embodied in coils for other types of transformers, as Well as in coils for other purposes. I do not wish my invention limited in other respects except as restrictions may be imposed by the prior art.

I claim as my invention 1. A coil for electrical apparatus comprising a plurality of snitablydnsulated strands disposed one outside of another and in an unequal number of side-by-side sections or turns,

the strands of the middle turn or section being bent across each other so that substantially one half of each strand occupies a complementary relation to the other half as regards distance from the center of the coil.

2. A coil for electrical apparatus comprising a plurality of suitably-insulated strands disposed one outside of another and in a plurality of side-by-side sections or turns, the strands of one of the sections or turns being bent across each other so that approximately one half of each strand occupies a complementary relation to the other half as regards distance from the center of the coil.

3. A coil for electrical apparatus comprising a plurality of suitably-insulated strands disposed one outside of another and transposed at a suitable point so that the active lengths thereof become approximately equal.

L. A coil for electrical apparatus comprising a plurality of suitably-insulated strands which are transposed at one or more points so that the active lengths thereof become approximately equal.

5. A coil for electrical apparatus comprising a plurality of strands in parallel and disposed in a plurality of turns or sections, the strands being crossed at one end of at least one of the turns or sections so that each strand occupies complementary relations at the sides of said turn or section.

6. A coil for electrical apparatus comprising a plurality of turns of multiple strands disposed side by side in the planes of the turns, the several strands in the middle turn occupying complementary relations at the sides of the coil as regards distance from its center.

7. A coil for electrical apparatus com p rising three turns of multiple-wound strands disposed in the planes of the turns, the strands at the sides of the middle turn occupying complementary relations as regards distance from the center of the coil.

In testimony whereof I have hereunto sul scribed my name this 12th day of March, 190%.

JOSEPH \V. FARLEY.

l/Vi tnesses:

HONORIA L. DOUGHERTY, BIRNEY HINns. 

